Waste not wanted

Published in the Antarctic Sun

McMurdo Station is the largest human settlement on the continent of Antarctica. More than
1,000 people will call it home this summer.

It’s an around-the-clock operation that generates sewage 24 hours a day. That waste is piped into the ocean less than 200 feet from the shoreline.

Two researchers are studying the impact the sewage outflow has on the McMurdo Sound ecosystem and on the quality of drinking water at the station.

John Lisle and Jim Smith are examining samples of ocean-floor sediment, the seawater, Weddell seal feces and McMurdo’s drinking water for evidence of human bacteria and viruses.

The first two are primary sources for a baseline indicator of how much pollution the sewage is introducing into the slow-moving ocean off McMurdo Station.

Seal feces help show the degree to which human bacteria have become part of the ecosystem, possibly causing disease in the seal population.

The drinking water studies are the first to test for viruses in McMurdo’s fresh water supply. The station’s water is regularly tested for bacteria and other contaminants, including lead.

The three major indicators the pair are looking at are fecal coliform bacteria, a common indicator of water quality used in judging safety of beaches and shellfish, clostridium perfringens, a bacterium associated with human sewage, and human enterovirus, which is found in human
feces.

Seal exposure
Lisle and Smith will compare the genetic material in bacteria in sewage and in similar bacteria in seal feces to see if the human bacteria are exchanging genetic information with bacteria in seals.

“Nobody knows if seals normally have clostridia,” Lisle said. He said they are also trying to find some seals that would not have been exposed to human waste, to give them a baseline level of clostridium bacteria in seal feces.

They hope to learn whether human diseases are being transmitted to the seals.

Two teams of researchers studying Weddell seals in McMurdo Sound are helping the pair by collecting samples of seal feces.

Outfall sampling
Science support diver Rob Robbins is collecting samples of water and the ocean floor around the sewage outfall.

Previous work has shown clostridia in sediment layers containing fecal coliform, and defined the physical extent of the pollution from the sewage outfall.

One of the problems was the concentration of waste in a location where the water doesn’t do much to dilute it.

“There aren’t very high current speeds here , ’’Smith said.

The end of the pipe, Robbins said, is 180 feet offshore in an area where the bottom is 60 feet deep. The pipe is raised four feet off the sea floor.

Since the new Crary aquarium was built five years ago, it flushes 250 gallons of cold seawater through the system each minute, Robbins said.

It used to be that the pile would grow over the course of a season to the height of the pipe. Now, Robbins said, with the increased flow from the aquarium in Crary, the waste has spread more thinly over a large area.

“Now it’s this huge field of effluent. It’s mostly poop out there,” Robbins said.

“Most of the pieces are about as big as your fingernail.”

Robbins talked about the spiny sea urchins that like to try to camouflage themselves with debris from the ocean floor.

Normally, they use other animals or bits of coral or other normal sea-floor debris. Near the outfall, though, Robbins said, “You see them with pretty interesting things.”

“I like diving at the outfall,” Robbins said. “You see things you’d never see anywhere else.”

Drinking water quality
The sewage plume extends beyond the intake for McMurdo’s water supply, but this has not been a problem in the past.

“The drinking water quality’s always been fine,” Smith said. But they are testing the water in a new way.

“This is the first time that viruses have been looked at,” Lisle said.

Both are clear, though, about the outfall’s role in transmitting contagious disease on the station.

“You can’t get the Crud from the sewer,” Smith said.

The samples of drinking water will be sent to the University of Arizona for analysis of viral presence; the results will not be available until the scientists return home.

Sewage treatment
“With the Antarctic Treaty, all the treaty signers are held to various standards for pollution and waste,” Smith said.

Some Antarctic bases do treat their waste already, including an Australian base, Smith said. New Zealand is planning to build a sewage treatment plant at Scott Base. McMurdo’s current macerator system meets the treaty requirements.

“Doing sewage treatment down here is a real challenge,” Smith said. Other places, he said, use big lagoons or oxidation ponds.

“ You can’t have that here. It’d just freeze solid,” he said.

Blasting began last week for McMurdo’s new sewage treatment plant, which will be running in 2003, said NSF facilities manager Frank Brier. The sludge from the plant, Brier said, will be sent back to the U.S. for disposal. The water leaving the plant will be treated to kill viruses and bacteria to prevent further pollution of the ocean.

“What is discharged (from the plant) is not drinkable but it’s clean,” Brier said.

Science roundup

Published in the Antarctic Sun

As summer returns to Antarctica, scientists and science support staff around the continent gear up for the prime research season. On the U.S. research vessels Laurence M. Gould and Nathaniel B. Palmer and at McMurdo, South Pole and Palmer stations, over 600 researchers will work on over 130 separate science projects. Here are some of the highlights of the upcoming science season:

ITASE
The International Trans-Antarctic Scientific Expedition will continue its journeys in East Antarctica, looking at shallow ice cores, showing climatic data from the past 200 years or so. (Corrected: West Antarctica.) Most global climatic data shows general trends of warming and cooling through Earth’s history, according to Bernie Lettau, the NSF science representative at
McMurdo Station. But climate also includes smaller areas. Global fluctuation is punctuated by more localized changes.
“There still have to be regional differences,” Lettau said. ITASE will continue to look at the actual data for the recent history of Antarctica.

SOAR
The Support Office for Aerogeophysical Research will fly over the area of Lake Vostok and Russia’s Vostok Station to study the area more closely. The information will be used in preparations for further study of Lake Vostok.
“It’s so they can make some educated decisions about what to do,” said Crary Lab supervisor Robbie Score.

The Crud
John Lyle is studying the McMurdo Crud, the illness that can strike McMurdo residents each season. The viruses survive in the air as well as in the sewage outfall into McMurdo Sound. They are not native to the area, and so they affect the water quality and the wildlife around the station.
“What they’re trying to do is see how our viruses influence the indigenous populations,” Score said.

Sea ice
John Dempsey of Clarkson University is studying the structure of sea ice, including how it forms and how it breaks up. The group is based near the edge of the fast ice of McMurdo Sound.
“They’re cutting a floe out and they’re going to start a crack and put weights on either side,” Score said.

Decoding ice cores
A team at South Pole Station is looking at how atmospheric particles end up in icecore sediments. Interpreting ice cores, Lettau said, requires an understanding of how the layers form. The team, led by Doug Davis of the Georgia Institute of Technology, is specifically targeting sulfur chemistry because of the significance of sulfur deposits in ice.
“Sulfates in ice are a primary proxy for reconstructing the climatic history from the core,” Lettau said.

GLOBEC
The Southern Ocean Global Ocean Ecosystems Dynamics study group will spend their first summer looking at krill as part of a summer-winter-summer set of cruises to look at the basic element of the Antarctic food chain.
“It is intended to look at the health of these various niches in the ocean ecosystem,” Lettau said. “What do krill eat when they’re under the ice in winter? Are they happy there?”

Scott Base
Antarctica New Zealand are supporting several projects this summer season, including a study of methods of preserving the historic huts on Hut Point, Cape Evans and Cape Royds. Also this season, Scott Base will see a series of interviews designed to compare people’s expectations
about Antarctica and their actual perceptions upon arrival, several ecological and environmental studies and a study of Adélie penguin populations at capes Crozier, Royds and Bird, which is one of several collaborative efforts between U.S. and New Zealand scientists. The equipment
used in the Cape Roberts drilling project, which was stored on Cape Roberts over the winter, will be returned to Scott Base this season.